RT Journal Article
SR Electronic
T1 Recombinant thyrotropin stimulation improves 18F-FDG PET/CT sensitivity in patients with recurrent differentiated thyroid cancer
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1308
OP 1308
VO 52
IS supplement 1
A1 Stefano Panareo
A1 Roberta Rossi
A1 Corrado Cittanti
A1 Melchiore Giganti
A1 Napoleone Prandini
A1 Paola Franceschetti
A1 Vincenzo De Biasi
A1 Silvia Lunardon
A1 Luciano Feggi
YR 2011
UL http://jnm.snmjournals.org/content/52/supplement_1/1308.abstract
AB 1308 Objectives To evaluate if the stimulation with Recombinant Thyrotropin (Rh-TSH) would improve the sensitivity of 18F-FDG PET/CT (PET) in patients with Differentiated Thyroid Cancer (DTC) in progression with high Thyreoglobulin (Tg) levels and both negative 131I Total Body Scintigraphy (TBS) and PET performed 6 months earlier. Methods We studied 10 patients with DTC in progression and both negative 131I TBS and PET performed 6 month earlier. All patients went pre-treated with Rh-TSH before PET. Tg and TSH levels were evaluated before and 24-48 hours after the injection of Rh-TSH. PET was performed using a dedicated PET-CT tomograph. Results Tg levels after Rh-TSH were within 2.1 and 27.6 ng/ml and they were unchanged in all patients compared to 6 months before. PET with Rh-TSH and Tg levels from 6.4 to 27.6 ng/ml was positive in 6 cases (mean SUV max 4.9) showing a direct correlation between Tg level and FDG uptake (p<0.1). Of these 3 showed right paratracheal radiotracer uptake not observed on UltraSonography (US) ad Computed Tomography. Three cases showed a laterocervical FDG uptake confirmed by US. All PET findings were confirmed by histological analysis after lymphadenectomy. Two patients with Tg levels respectively of 3.4 and 3 ng/ml showed no tracer uptake on PET and they were followed. Two patients with negative PET and Tg levels respectively of 8 and 11.7 ng/ml were re-treated with 131I because of the US localization of loco-regional disease recurrence. Conclusions PET seems to be better then conventional diagnostic image for the localization of lymph node recurrence of DTC in progression after Rh-TSH stimulation showing a direct correlation between Tg level and SUV max. Our results suggest that the Rh-TSH stimulation can improve the diagnostic sensitivity of PET in patients with DTC in progression changing their therapeutic strategy and follow-up. Our data must be confirmed in a larger casuistry